1. Field of the Invention
The subject invention is directed to a method for preventing chaffing between a linear detector cable and a protective outer sheath in a terminal transition region, and more particularly, to a method of constructing a sheathed linear detection cable with transition protection to prevent chaffing.
2. Description of Related Art
Linear heat detection cables are commonly used for fire detection. They typically include a two-core cable terminated by an end-of-line resistor, the form of which varies by application. The two core wires are separated by a polymer plastic, that is designed to melt at a specific temperature, and without which causes the two core wires to short. This can be seen as a change in resistance in the wire, which can be detected anywhere along the length of the cable. Applications can range from building fire alarm systems to transportation systems.
In vehicular applications, these cables are often mounted within an engine compartment where they are subject to a harsh environment including intense radiant heat, sources of abrasion and constant vibration during vehicle operation. In view of the harsh environment, it is advantageous to cover the relatively delicate detection cable with protective sheathing, which can protect it against abrasion and reflect radiant heat.
For example, in certain applications, it has been found to be advantageous to protect the linear heat detection cable within a flexible stainless steel conduit. However, in such a configuration, there will be an unprotected portion of the detector cable that will extend from the open end of the conduit. That open end will typically have sharp surfaces, and these surfaces can potentially chaff the polymer covering of the detection cable, especially in an operating environment that experiences continuous vibrations. This could cause the core wires to short unnecessarily, rendering the linear detection cable inoperative.
It would be advantageous therefore, to provide a method for preventing chaffing between a linear detector cable and a protective outer sheath in a terminal transition region between the ends of the sheath and the connector component of the liner detector. The subject invention provides such a solution.